High-density information discs require a lubricant on their surface to reduce the sensitivity of the discs to atmospheric contaminants and to reduce wear on the playback stylus. The present commercial lubricant is a fractionated and purified methyl alkyl siloxane having the formula ##STR2## wherein R.sub.1 and R.sub.2 are alkyl groups of 4-20 carbon atoms, x is an integer of 2-4, y is an integer of 0-2 and wherein the sum of x and y is 4 or less, made according to the method described in U.S. Pat. No. 4,275,101 to Wang et al.
However, this lubricant system is sensitive to atmospheric conditions such as high temperature and high relative humidity and results in a phenomenon known as "carrier distress". Moisture dissolves certain impurities and salts on the disc's surface forming a solution. When the water evaporates, it leaves a salt deposit on the disc that causes the playback stylus to jump out of the information track, resulting in streaks or blackouts of the picture information observed by the viewer. If the deposits are exceptionally large, the stylus may skip over several grooves, leading to interruption of both sound and picture information. Depending on the length and frequency of the interruptions and skips, the record becomes commercially unacceptable.
Thus various dopants have been added to the lubricant to reduce carrier distress and skips. Generally effective dopants are polar compounds, but there is no way at present to predict whether a particular material or class of materials will be effective dopants. Known dopants include bis(hydroxyalkyl)disiloxanes, described in U.S. Pat. No. 4,355,062 to Wang et al, and hydroxylated amines such as are described in U.S. Pat. No. 4,330,583 to Datta et al. The former, while it has a pronounced positive effect on carrier distress, is a very expensive material. The latter has the disadvantage that it is not soluble in the methyl alkyl siloxane lubricant and thus must be applied separately or from a mixed solvent solution.
Several trimethoxy silanes have been tried as lubricants, but, while they do improve skip performance marginally, they are not effective to reduce carrier distress to a satisfactory level.
Thus the search for effective additives to methyl alkyl siloxane lubricants which will reduce carrier distress has continued.